Perhaps I can assist in outlining how to get rid of this nest by describing one way NOT to do so.
When I was a kid, we had a hornets nest in a conifer-pine type of ornamental tree that was just off a corner of our house. The tree was about twenty feet tall.
I can't recall who's idea it was, but we decided to burn them out. We located a long stick about 10' long, tied a rag to the end, and soaked it in gasoline.
You know how conifer type trees or bushes are green on the outside, but dead & brown on the inside?
Well, that tree lit up like the 4th of July. The house survived, but the tree did not. No hornets left either.